الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 140 |  |  |
| | | from | 140 | | |
Abstract
Environmental conservation activities have been promoted as a global must to control dramatic pollution crisis that impact our natural resources. Environmental authorities, organizations, foundations, affairs and even suburban centers over the world are implementing international, local co-operation projects specially to developing countries in order to provide the best environmental pollution control tasks. Throughout history the quality of water has been the factor in determining human welfare, Since the second world war, there has been a tremendous growth in the manufacture and use of chemicals.
Currently, waterborne toxic chemicals pose the greatest threat to the safety of water supplies. There are many possible sources of chemical contamination. Many of the chemicals have contaminated water supplies as industrial discharge into surface water. Although there is a threat to ground water supplies from waste chemical pumps and landfills storage lagoons, treating ponds, and other facilities.
Electroplating is the process of plating one metal onto another by electrolysis, most commonly for decorative purposes or to prevent corrosion of a metal. Electroplating allows manufacturers to use inexpensive metals such as steel or zinc for the majority of the product and then apply different metals on the outside to account for appearance, protection, and other properties desired for the product. Electroplating is widely used in industries such as automobile, airplanes, electronics, toys and chandeliers. Chandeliers can be used as general illumination and as a decorative complement of the décor, although they can be a source of
100
glare if the wattage is too high and they cannot be dimmed. The body of the chandeliers is subjected to electroplating.
Electroplating industry consumes and discharge large volumes of wastewater. Use of various chemicals and metal salt creates pollution
problems. Major pollution caused by rinse water, spray losses and solution dumping and leakages. Valuable metals along with different chemicals used are lost in wastewater. The amount may be 2-20% of the metal used.
Therefore, great efforts shall be required to reduce the pollution problems. The effluent concentration depends on various factors such as surface area, shape of article, thickness of solution, speed of removal, drain time etc.
This effluent is supposed to be the most hazardous containing heavy metallic ions such as nickel, zinc, copper, etc., as well as cyanides, hydrogen sulphides, ammonia, chloramines which are toxic but valuable.
Hence complete detoxification should be achieved before the
effluent is discharged in aquatic stream. Many physico- chemical processes are employed for the removal of impurities and to reduce pollution load. Chemical coagulation and electrocoagulation are effective method in removing a wide range of impurities which include dissolved organic matter, pathogens, and colloidal particles as well as heavy metals.
As evidenced in this study, removal of some heavy metals resulted from wastewater of chandlers electroplating factory is occurred by electrcoagulation process.
101
In chapter 1: general introduction of heavy metal and environmental pollution, electrochemistry and electrochemical cells, electroplating process and its applications.
In chapter 2: methods for Removing Heavy Metals from Industrial Wastewater, coagulation and electrocoagulation.
In chapter 3: experimental section of electrocoagulation of electroplating effluent using different type of electrodes and comparing between them in their efficiency for removing heavy metals.
The electroplating effluent solution was passed through a flow-through electrochemical treatment cell consisting 6 parts, the stainless steel electrodes assembly in two parallel electrodes in each part of cell and connected with direct current DC in monopolar electrode with parallel connection. Experiment was run at room temperature 25o C at constant Voltage 10 voltage and flow rate 100 ml/min.
In chapter 4: the results of study on the electrocoagulation of electroplating effluent using soluble electrode (iron and aluminum electrode) and insoluble electrode (carbon and stainless steel) with ferric chloride as coagulant. These results proved that stainless steel electrode with ferric chloride as coagulant is the most effective electrode for removing zinc, copper and nickel ions from effluent than any other electrode. So, stainless steel is applied on synthetic solution then on factory sample. The removal efficiency for synthetic solution of zinc,
102
copper and nickel is 97.5%, 97.2% and 97.1% respectively and for factory sample is 100%, 99.6% and 99.8%, this results is agreeing with environmental laws so, it can be discharged easily into water streams.
By applying the treatment cell unit, it has been found that:
The removal efficiency for synthetic solution of zinc, copper and nickel in the treatment cell in (Batch reaction) is 98.8%, 98% and 97% respectively
The removal efficiency for synthetic solution of zinc, copper and nickel in the treatment cell in (continuous flow reaction) is 98.5%, 97.8% and 97.4% respectively.
The removal efficiency for factory sample of zinc, copper and nickel in the treatment cell in (Batch reaction) is 100%, 99.9% and 99.7% respectively.
The removal efficiency for factory sample of zinc, copper and nickel in the treatment cell in (continuous flow reaction) is 99.9%, 99.9% and 99.9% respectively. This results is agree with environmental laws so, it can be discharged easily into water streams.